Life raft release device



June 24, 1958 w, c. SIEVERTS 2,839,767

LIFE RAFT RELEASE DEVICE Filed Jan. 18, 1956 FIG. '4 22 8 K i I 04k 1 x E A.. k

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' INVENTOR. WILLIAM C. SIEVERTS ATTO RN EYS 2,839,767 LIFE RAFT ,RELEA-SE DEVICE William C. Sieverts, Kingston, Mass.

Application January 18, 1956, Serial No. 559,886 6 Claims (or. 9-33) This invention relates generally to releasable coupling devices for use with life rafts and other buoyant life saving devices. .The object of the invention is to provide a mechanism, which upon submergence of the ship with a life saving device secured to it, will automatically free .the life saving device promptly, so that it will float to the surface and thereby be available to .a person who may be swimming in the water.

Life saving rafts and the like have usually been lashed 7 United States Patent() This is not suflicient, however, in those I In the patents to Sieverts, No. 2,336,967, and to Bryant, 7' 3 No. 2,360,848, an automatic releasing mechanism is shown which is actuated by water pressure, which pressure increases as the ship progressively sinks to a greater depth. In the devices of the prior art, however, a very heavy load was continuously exerted by the force of the lashings on the pins that held the coupling device together as it :acted in its normal capactiy with the ship afloat. This heavy pressure combined with possible corrosion and/or paint on the holding pin oftentimes resulted in failure of the holding pin to be removed in spite of the pressure exerted on the hydraulically actuated removing mechanism by the Water.

Accordingly, it is an object of this invention to improve upon the devices of the prior art by providing a construction in which frictional force effective on the holding pin that is to be removed by the increasing water pressure applicable as the boat sinks, is of a relatively low degree so that small water pressure is required to remove the pin, thus freeing the life raft when the boat is but a short distance below the surface.

Another object of the invention is to provide a release device which alternately may be operated manually so that the life raft may be freed at any time desired without dependence upon the automatic releasing mechanism which comes into play only as the ship is sinking.

These and other objects of the invention will become more apparent as the description proceeds with the aid of the accompanying drawings in which Fig. 1 is a side elevation of the device with the near face plate removed.

Fig. 2 is a side elevation looking from the right of Fig. 1 with both face plates in position.

Fig. 3 is a section on the line 33 of Fig. 1 drawn to enlarged scale.

Fig. 4 illustrates the coupling device in operative position whereby it is holding a life raft in a selected location on the ship prior to releasing.

Fig. 5 shows the relative movement of the parts after the release of the hydraulically actuated releasing pin.

The releasing coupling device is generally referred to by the numeral 2 and comprises a supporting frame consisting of a rear faceplate 4 and a cover face plate 6 separated from each other and having certain operative elements secured therebetween. A stirrup 8 is held in place between the'face plates by means of rivet 10 which extends through the small eye 12 of the stirrup and corresponding holes in the two plates 4 and 6.

Two pivoted levers 14 and 16 are also 7 maintained between plates 4 and 6 rotating on their respective pivots 18 and 20. The levers 14 and 16 are, under normal conditions, held against rotation by pins 22 and 24 which extend through the plates -4 and 6 and through holes 26 and 28 at the ends of the levers.

The pins 18 and 20, on which the levers pivot, likewise extend through the plates 4 and 6, as may be seen from Fig. 2. The lower ends of levers 14 and 16 have hooklike portions 30 and 32 which when in the position shown in Fig. 1 hold between them the upper cross-wise extension 34 of the lower releasable stirrup 36.

The rear face plate 4 has a lateral semi-circular extension 37 to which is secured a housing 40 by rivets or other suitable securing means 38. .This housing comprises an upper member 42 having a plurality of open ports 44, and a cover 46 secured to the member 42 by a plurality of bolts 48 passing through the flanges 47 and 49. A diaphragm 50 secured between the flanges separates the interior 52 of the cover from that area 54 that is accessible to the atmosphere and water through ports 44.

The diaphragm may be made of any suitable material such as synthetic rubber, which will stay in good, usable condition for long periods of time. At the center of the diaphragm is an aperture in which is positioned a tubular stud 56 with a fiange58 which overlies the diaphragm. This stud is threaded at 60 and a nut 62 threaded on the stud secures a stiffening disc 64 in position on the underside of the diaphragm. Pin 22 extends through the stud and is secured in watertight relation thereto in any convenient manner as by the indented prongs 66. A coil spring 68 positioned over a tubular pin guiding element 70 acts to maintain the diaphragm and pin in maximum upward position, which upward position is limited by engagement of stud 56 with the under surface of member 42.

With the parts in the position shown in Fig. 1 it is apparent that the device 2 may be utilized as schematically shown in Fig. 4 to maintain a raft 72 in position on a boat .by means of lashings 74 running from a rail 76 to stirrup 36 and other lashing 78 running to another point of support. Obviously a variety of lashing arrangements may be used utilizing the releasable coupling.

When it is desired to free the raft from its secured position, this may be accomplished either by manually removing pin 24 or by removing pin 22, which may be done by applying suflicient pressure to the upper surfaceof diaphragm 50. This pressure will be applied by the water as the ship is sinking.

It makes no difference with respect to the release of the raft whether it is accomplished by removing pin 22 or pin 24. In either event the'elfect on the released stirrup 36 will be the same. The nature of the release of stirrup 36 is shown in Fig. 5. In this case, pin 22 has been removed from its normal position through the face plates and hole 26 in the upper end oflever 14. When this happens the pull of extension 35 of stirrup 36 against hook 30 causes the lever 14 to swing clockwise as shown in Fig. 5 thereby freeing'the upper end of the stirrup 36 so that it may separate from plates 4 and 6. This, in turn, frees lashings 74 thereby permitting the raft 72 to float to the surface, thereby to achieve the end result desired.

The distance between the lower end of pin 22 and,

the bottom of the cover 46 is great enough so that pin 22 under the influence of water pressure on diaphragm 50 will be able to move downwardly far enough to clear lever 14, thereby permitting the lever to swing in the manner shown in Fig/ 5;

It-Will be understood that thespacing between plates 4 and 6 and the fit of the pins 18 and 20 in levers i4 and '16 is such that the levers may pivot freely once they have been released by the removal of pin 22 or pin 24. a

If pin 24 is released the movement of lever is will be counter-clockwise to correspond with the movement of lever 14 as shown in Fig. 5.

The advantage of the foregoing described construction over the prior art :is this: The principal portion of the load applied to the device through the tension of the lashings 74 on the stirrup 36 is through the pins 18 and 26. The only loadthat' comes on pins 22 and 24 is that resisting the turning tendency of the two levers l4 and 16, which turning tendency is determined by the angularity of the hook faces 80 and 82. The more vertical these faces, the greater the load on pins 22 and 24. In the design of faces 86 and 82 a compromise angle is taken designed to place as much load as possible on pins 18 and 26 while at the same time insuring that lever 14, for example, will rotate freely to the position shown in Fig. 5 upon the removal of pin 22.

From the foregoing explanation it will be seen that the frictional forces acting to prevent the removal of pin 22 with the device in normal secured position are relatively small compared with the prior art constructions and therefore, it requires relatively small pressure applied to diaphragm 50 to move pin 22 downwardly out of the hole 26 of lever 14. The great advantage of this reduced frictional characteristic between pin 22, plates 4 and 6 and lever 14 is that the pin will be released after the ship has gone under the surface a less distance as compared with the prior art devices which because of the high friction on the releasing pin required that the ship sink to a much greater depth before the holding pin would be released. Similarly, it is easier to release pin 24 by pulling on the ring 34.

it is my intention to cover all changes and modifications of the example of the invention herein chosen for purposes of the disclosures which do not constitute departures from the spirit and scope of the invention.

I claim:

1. A coupling device for releasably holding together the lashings of a life raft, said device comprising a supporting frame, opositely disposed elements for receiving said lashings, one of said elements fixed to the frame, two members carried by said frame for engaging and 4 holding the other of said elements, said members being pivoted on said frame and each maintained in position by a removable pin, each of said members upon removal of its said pin adapted to swing on its said pivot under the turning force exerted thereon by said other element thereby to free said other element.

2. A coupling deviceas set forth in claim 1, one of said pins associated with an hydraulically operated mechanism for removing said one pin when said device is submerged to a predetermined depth in water.

3. A pling device as set forth in claim 1, the turning force exerted on said members by said other element being accomplished by' having the engaging portions thereof meeting at an angle less than 90 with respect to the direction of pull of said lashings.

4. A coupling device for releasably holding together the lashings for a life raft, said device comprising a supporting frame, a pair of oppositely disposed stirrups to which said lashings may be attached, one of said stirrups fixably secured to said frame and the other stirrup releasably secured to said frame, laterally extending elements on said other stirrup, a pair of levers pivoted to said frame, each of said levers maintained in fixed position by a pin engaging said frame. and lever, each of said pins being disengageable from its said lever, a portion of each of said levers engaging the underside of one of said laterally extending elements along a sloping line of contact, the slope of the said line of contact of said engaging portions of said levers and said elements being such that upon release of either of said pins from said levers the released lever will turn under the force applied by the said other stirrup, thereby to release said other stirrup and lashings.

5. A coupling device as set forth inclaim 4, the distance from the pivots of said levers to said pins being greater than the distance from said pivots to said engaging portions and elements.

6. A coupling device as set forth in claim 4, one of said pins associated with an hydraulically actuated means, whereby upon submerging said device to a predetermined depth in water one said pin will be disengaged from its lever.

References Cited in the file of this patent UNITED STATES PATENTS 1,214,313 Kalbileisch Ian. 30, 1917 1,842,014 Edwards Ian. 19, 1932 2,336,967 Sieverts et al Dec. 14, 1943 2,360,848 Bryant Oct. 24, 1944 

